1, Field of the Invention
The present general inventive concept relates to an array head type inkjet image forming apparatus and a method of compensating for alignment errors thereof. More particularly, the present general inventive concept relates to an array head type inkjet image forming apparatus which can control driving of nozzles in areas in which head chips overlap with each other, and a method of compensating for alignment errors thereof.
2, Description of the Related Art
An image forming apparatus is an apparatus which prints a color image on the surface of a printing medium by firing minute droplets of printing ink onto a desired location on the printing medium. Inkjet printers can be divided into shuttle type inkjet printers and array head type inkjet printers.
The shuttle type inkjet printer can form an image by projecting printing ink from a printer head reciprocating in a perpendicular direction with respect to a transferring direction of the printing medium. In contrast, the array head type inkjet printer is provided with a printer head having a plurality of head chips. In other words, in the array head type inkjet printer, width of the printer head having a plurality of head chips is equal to or wider than width of the printing medium, so an image can be formed by transferring only the printing medium if the printer head is fixed, or by moving the printer head in the main projecting direction.
In order to prevent degradation of image quality that may occur at the boundaries of the plurality of head chips due to the intervals between the plurality of head chips, the array head type inkjet printer described above is manufactured in order that the plurality of head chips overlap with each other.
In order to prevent the degradation of image quality, the location of the printer to which the plurality of head chips are attached is precisely determined through numerous tests in advance, making it possible to prevent generation of nozzle alignment errors in which the plurality of nozzles provided on the plurality of head chips overlap with each other.
However, since the nozzles overlapping with each other between the plurality of head chips have a radius of no more than several micrometers to several tens of micrometers, it is difficult to attach the head chips minutely in a real manufacturing process such that the nozzle alignment errors can be prevented, and the head chips may therefore be arranged with intervals of less than 1 nozzle in order to generate a white line or a black line on the boundary of the head chips.
In this case, other methods may be performed, attaching the head chip in order to prevent the nozzle alignment errors using more minute apparatus, or measuring the number of overlapping nozzles by directly printing image patterns. However, considering time, expense, and technological prowess rendered therein, the methods are not economical.